In a motor-driven chain saw of the type disclosed in German published and examined patent application DE-AS No. 1,528,028, a centrifugal clutch is arranged at the outer output end of the crankshaft. At a suitable rotational speed, the radially movable clutch members are forced outwardly against the inner surface of the peripheral wall of a substantially cup-shaped clutch drum. The clutch drum is open at the output end of the crankshaft and includes a sprocket at its base wall. The sprocket is rotatably journalled on the crankshaft and drives the saw chain.
Adjacent to the sprocket is a drive wheel which is also rotatably journalled on the crankshaft and is rigidly connected to the sprocket in the close vicinity of the crankshaft by means of at least one axially parallel pin. The drive wheel drives a pump for pumping lubricating oil.